Biodegradable calcium phosphate coating on Ti6Al4V by sol-gel process

摘要

Biodegradable calcium metaphosphate (CMP) sol was prepared and then coated on Ti6Al4V substrates by spin-coating technique. In order to investigate the effect of hydrolysis time of (OC_2H_5)_3P on the reaction with Ca(NO_3)_24H_2O, the P-precursor was pre-hydrolyzed for 1, 5 and 10 hours before the reaction with the Ca-precursor. At least above 5 hours of pre-hydrolysis of P-precursor were required to obtain beta -CMP. The CMP coated specimens were dried at 70, 100, and 130 deg C, respectively and then heat-treated at 630 deg C for 3 hours with and without holding at 476 deg C for 2 hours. It has been found that the drying temperature of the CMP coated specimens was one of the most important factors affecting the homogeneity of the coating layer. The optimum drying temperature was 70 deg C, and the CMP coated layer with holding at 476 deg C during firing was homogeneous and had fewer cracks, compared with that of sample without holding.